This invention relates to the adjustment of the steering angle of one of the two wheels on a vehicle to obtain an optimum steering angle for the combination of the two wheels.
Vehicles typically incorporate two axles spaced along a center line of the chassis of the vehicle. Typically, the front axle includes steerable wheels, and the rear axle includes non-steerable wheels. It is a known challenge to the designer of steering systems that one of the two wheels will often be subject to scrubbing during a turn. This results in high tire wear. Typically, scrubbing occurs since the radius upon which an inner of the two wheels will travel is less than the radius upon which the outer of the two wheels will travel.
This basic arrangement is often called an Ackerman geometry steering system. With Ackerman geometry steering systems, it is known that there is only one turning angle combination for the two wheels which will result in an optimum overall steering to minimize scrubbing.
The optimum angle is one in which the projected axes of the two turned steering wheels intersect each other along a projection of the rear axle axis. In such a combination, the two steered wheels will have a pure rolling motion, and scrubbing will be reduced if not eliminated. For all other turning angles, there is an error between the angle of one of the steered wheels and the optimum value. This error causes undesirably high tire scrubbing and resultant tire wear.